1. Field of the Invention
The present disclosure relates to systems and methods for marking a target, and in particular, to systems and methods for marking a target with thermal radiation.
2. Description of Related Art
In combat arenas, some target marking applications may require use of radiation, such as a thermal beam, to mark targets in a way that may not be detectable by the target. For example, since thermal beams are not visible with the naked eye or with common infrared viewers, a soldier or other user of a thermal target marking system may be able to identify and/or otherwise mark a potential target without the target being able to see, for example, a targeting dot on his person. However, use of thermal radiation to mark targets is not without its own inherent complications.
A quantum cascade laser (“QCL”) may be utilized to emit thermal beams in such applications, however, because the beams emitted by QCLs are inherently divergent, employing a QCL in such applications typically requires additional componentry configured to shape the thermal beam. For example, known beam shaping techniques may be used to increase the resolution of the thermal beam, thereby allowing the beam to appear smaller when impinging upon the target. However, such shaping techniques typically reduce the intensity of the thermal beam. Thus, the resulting beam, although desirably narrower, may be difficult for thermal beam detectors to view at great distances. As a result, such marking systems may be undesirable for use by, for example, snipers or other medium to long-range combat applications.
In addition, QCLs are inherently inefficient as light sources. For example, most typical QCLs give off a great deal of heat relative to the amount of light produced when the QCL is provided with an electrical current or voltage. While this inherent inefficiency may not be terribly problematic in a laboratory or other environment in which power and cooling components can be adapted relatively easily for use with such QCLs, such inefficiencies make it much more difficult to utilize QCLs in, for example, hand-held target marking devices or other devices in which space, weight, mobility, and/or other parameters are much more tightly constrained.
For example, utilizing a QCL in a hand-held target marker typically requires the use of one or more portable power sources such as, for example, batteries or the like. Because such batteries are generally low energy power sources, and because such batteries may only be capable of providing power for a limited time, utilizing such batteries to power a relatively inefficient QCL can be problematic. For example, such batteries may be depleted relatively quickly due to the large power draw placed on them by the QCL. In addition, even when powered by such batteries, the QCL may give off substantial amounts of heat and may require one or more cooling components to be thermally connected thereto to optimize QCL performance. Such cooling components may represent an additional parasitic load on the batteries being utilized, and may further reduce the useful life of such batteries. Due to these difficulties, the use of QCLs in hand-held or other portable target marking devices has been limited.
The embodiments of the present disclosure are aimed at overcoming one or more of these deficiencies.